Method of making decalcomania papers



April 7, 1936. J. MacLAURl N 2,036,422

METHOD OF MAKING DECALCOMANIA PAPERS Filed Aug. 10, 1955 @QQQQQ Patented Apr. 7, 1936 PATEN METHOD OF MAKING DECALCOMANIA PAPERS John MacLaurin, Ware, Mass.

Application August 10, 1933, Serial No. 684,529

1 Claim.

The usual method of making decalcomania paper consists in applying a suitable number of coats of adhesive to the surface of a backing sheet, which usually consists of paper carrying very little or no sizing so that it is readily penetrated by water. The decalcomania design may be printed on the surface of the adhesive so applied. In some cases a coating of lacquer or some other material-adapted to take the printing ink is applied to the surface of the adhesive coating and the printing is done on this lacquer or other surface coat. This'is a commonmethod of making the so-called slide off decalcomanias. The adhesives used for the purpose of making these papers usually consists of boiled starch or of a mixture of starch and dextrine, although other adhesive materialscan be employed for this purpose. Usually, also, it is necessary to apply more than one coat of such adhesives to the surface of the backing sheet, and the object is to produce a coating, as distinguished from impregnating or sizing the sheet. Because of this fact and the further fact that the backing sheet is highly pervious to water, care must be taken to make the coating ride on the surface or the sheet instead of penetrating it, where its effect would be to size the sheet and thus to destroy the desirable permeability of the latter.

The present invention relates to the methods of making decalcomania papers and it aims to effect economies in this process.

The nature of the invention will be readily understood from the following description when read in connection with the accompanying drawing, and the novel features will be particularly pointed out in the appended claim.

In the drawing,

Figure 1 is a diagrammatic side view illustrating steps in the process provided by this invention; and

Fig. 2 is a plan view of the apparatus illustrated in Fig. 1.

I have found it entirely practical to apply the first coating of adhesive required for decalcomania purposes to the surface of the backing sheet during the paper making operation. Referring to Fig. 1, the drying cylinders or drums of a paper making machine are indicated at 2 and the stack of calendar rolls at 3. The web'of paper W is shown travelling over these drums and rolls in the usual manner, said web coming from the paper making wire of a Fourdrinier or other suitable machine and travelling continuously through the drums and rolls to the winding mechanism. In the particular arrangement shown the drying drums are disposed in two groups with a space between these groups in which is located some source of continuous supply (here indicated as a reservoir 4) of a suitable decalcomania adhesive, such as starch or a mixture of starch and dextrine dissolved in a sufficient quantity of water so that it will flow fairly freely. A spout 5 equipped with a valve 6 conducts this adhesive from the bottom of the tank to a point closely adjacent to and immediately above the web W just in front of the point at which this web comes in contact with a guide roll 1. The spout is flared, as shown in Fig. 2, and consequently, it delivers the liquid coating material over quite a substantial width of the sheet. The roll 1 is either revolved idly by the sheet or may be driven, as desired, and the coating liquid is fed to the bite or crevice between the web and the roll and flows laterally toward both edges of the sheet. The rate of flow is so adjusted that practically the entire upper surface of the web from one edge to the other is coated with the adhesive. The extreme margins preferably are left uncoated, although this is not absolutely necessary. Any drip which overflows the margins of the sheet is caught in a pan 8. The roll I thus acts both to control the coating material to a considerable degree and also to spread it laterally from one margin to the other of the sheet.

After leaving the roll, the web passesbetween squeeze rolls 9 and Ill and then around the remaining drying drums 2 and through the calendar stack.

Considering the fact that the coating so applied consists of an adhesive material, and bearing in mind the further fact that the web, wet with this material, passes immediately into contact with heated drums, and considering further the high speed at which the web of paper travels through these paper making machines, it naturally would be assumed that the coated web would stick to and wind up on the drying drums and plug the machine. The use of this process in actual practice, however, has definitely demonstrated that this action does not occur and that this method of applying a coating of decalcomania adhesive is entirely practical. It efiects a substantial economy in the manufacture of this material for the reason that it performs, in the paper machine, one of the subsequent coating operations which has been necessary according to prior processes. The application of the coating to the web while it is travelling through the paper making machine does not add materially to the expense oi. manufacture of the paper, nor adversely affect the quality of the finished product. Consequently, a substantial saving is effected.

One of the finishing operations which normaliy is performed on the paper web consists in trimming the edges of the web, and the spreading of the adhesive toward the edges should be so controlled that the trimming required to remove the deckle edges will leave a web completely coated on one side with the adhesive.

While I have herein shown and described a preferred practice of carrying out this invention, it will be understood that the method may be practiced in other ways and with the aid of other forms of apparatus or machinery.

Having thus described my invention, what I desire to claim as new is:

That improvement in methods of making decalcomania papers, which consists in making a web of paper approximately devoid of sizing and of the highly permeable characteristics suitable for use as a backing sheet for decalcomania papers, during said manufacturing operations and after the partial drying of the web but before calendering it, flowing a coating of decalcomania adhesive on to the upper surface of the moving web of paper immediately above the point of contact of said web with a guide roll and at such a location that a supply of said adhesive will be held in the angle between said paper and the surface of said roll and will flow laterally and horizontally to points adjacent the deckle edges of the web, subsequently subjecting said web to the usual drying and calendering operations, performing all of said operations while the web continues to travel uninterruptedly, and subsequently trimming the uncoated edges of said web.

JOHN MACLAURIN. 

